EFFECTS OF EXERCISE ON HYPOGLYCEMIC RESPONSES IN INSULIN-DEPENDENT DIABETES-MELLITUS

This study sought to determine whether moderate exercise influences hy poglycaemic responses in insulin-dependent diabetes mellitus (IDDM). T en patients with IDDM and no history of hypoglycaemia unawareness or a utonomic neuropathy were included. The patients were studied in random order on 4 occasions :twice during euglycaemia lance at rest and once on a treadmill)and twice during a gradual drop in blood glucose from 5 to 2 mmol/l (once at rest and once on a treadmill). Blood samples fo r hormones and glucose were drawn, and a symptom questionnaire was fil led out every 5 min. Cognitive tests were performed at the start and e nd of each study. Glucose thresholds for hormones and symptoms are rep orted as the plasma glucose level at which responses were more than tw o standard deviations above basal level and continued to increase. The thresholds for adrenaline and noradrenaline release came at a signifi cantly higher blood glucose level during exercise than at rest: 2.7 +/ - 0.2 vs 2.1 +/- 0.2 mmol/l (p < 0.05) for adrenaline and 2.7 +/- 0.2 vs 2.0 +/- 0.1 mmol/l (p < 0.01) for noradrenaline. Thresholds for neu roglycopenic symptoms were also at a significantly higher blood glucos e level during exercise: 2.6 +/- 0.2 vs 2.0 +/- 0.2 mmol/l (p < 0.05). During hypoglycaemia, patients showed a nan-significant trend towards a lower score on cognitive tests during exercise than at rest. It is concluded that moderate exercise during a gradual drop in blood glucos e does not mask hypoglycaemic responses in patients with IDDM.